LUN Distribution Scenarios
Scenario 1: Multiple Target channels, single storage server channel
In this scenario, the storage target is connected via multiple paths to a switch. The storage server initiator (SDS) is connected via a single path to the switch. The red paths are the redundant paths. If any of the paths in red fail, then LUN Distribution will be able to utilize another red path.
Scenario 2: Single target channel, multiple storage server channels
In this scenario, the storage target is connected to the switch by a single path. The storage server initiator (SDS) is connected to the switch via multiple paths. The red paths are the redundant paths. If any of the red paths fail, then LUN Distribution will be able to utilize another red path.
Scenario 3: Multiple target channels, multiple storage server channels
In this scenario, the storage target is connected to the switch via multiple paths and the storage server initiator (SDS) is connected to the switch via multiple paths. Each storage server channel will see “n” number of target paths (assuming the switch is configured to allow each storage server channel to each target channel). In this configuration, there are nine possible failover choices.
Scenario 4: Two storage server configuration with inter-SDS mirroring
In this scenario, inter-SDS mirroring occurs over multiple channels with each channel acting as a failover possibility. Assume that each of the blue channels are for inter-SDS mirrors and the switch is configured so they can access each other. Inter-SDS mirrors can failover to any of the blue channels in any direction. So, each storage server initiator (SDS) has two possibilities for a failover (each inter-SDS mirror can be presented over each of the blue channels). In this scenario, access to the storage target is also redundant across the red channels.
